Hurricanes and Wildfires: How Climate Change Impacts Extreme Weather

Sep 12, 2017

Dr. Jon Meyer, a climatologist with the Utah Climate Center, said climate change will likely impact hurricanes in two key ways: through ocean temperatures and the jet stream.

When the ocean reaches 82 degrees, it begins to create the humid conditions that fuel hurricanes.

“Hurricanes are essentially engines that derive their fuel, their horsepower, from condensation of water vapor,” Meyer said. “So the more humid the atmosphere is, the more water vapor there

Credit climatesignal.org

is to condense and the more horsepower these storms can work with. We’re seeing this 82 degree threshold, we’re seeing those temperatures arrive earlier in the year and last later in the season.”

In addition to the impact of warming the oceans, climate change could also worsen hurricanes by slowing the jet stream.

Meyer describes the jet stream as “the shepherd of storms.” The jet stream is like a river of wind above the atmosphere, which exists because of the temperature difference between the poles and the equator.

“With climate change, we’re seeing the polar regions are warming up quite a bit faster than the rest of latitudes, and that modifies the difference in temperature between the tropical latitudes and the polar latitudes,” Meyer said. “So what we’re seeing is we’re slowing down the jet stream.”

And like a river, as it slows, the jet stream will start to meander more. This can cause blocking patterns, which trap weather in one place. Meyer said the flooding caused by Hurricane Harvey was made more severe by blocking patterns.

“If you’re a kayaker, if you know kayakers, they could be in this chaotic mountain river, but if they can find that calm spot right behind a big boulder where the water is pretty calm, then they can just sit there and relax,” Meyer said. “That’s kind of what Harvey did, in a sense.”

Blocking patterns can also worsen other kinds of severe weather.

“The California droughts in the last few years is a really good example, the western wildfires for this summer, really good examples of what happens when you get stagnant jet stream,” he said.

Meyer said these events may start a dialogue about how we as a nation can be more prepared for extreme weather.

“We’re really seeing the economic impacts that weather and climate can have on our society,” Meyer said. “And then you start to talk about the society impacts of what it means to a country of people that are seeing huge swaths of the population being exposed to these really dramatic and devastating events. If these events do increase in magnitude and severity, we may need to have some foresight on how we can mitigate the risks associated with climate and weather events.”